Speed control system



Jan. 18, 1938. GERLACH 2,105,529

SPEED CONTROL SYSTEM Fileq Aug. 6, 1935- M i i M 20 F J Zimnentor Era/warm (Ittorneg I Patented Jan. 18, 1938 I UNITED STATES SPEED CONTROL SYSTEM Erwin Gerlach, Berlinassignor to Klangfilm y,

Germany,

Siemensstadt,

Berlin, Ger- G. m. b. H.,

a corporation of Germany In Germany September 7, 1934 "Application August 6, 1935, Serial No.

This invention relates to speed control systems such as are utilized in connection with-sound recording and reproducing apparatus, and has for its principal object the provision of an improved apparatus and method of operation whereby means are operated in response to the driving speed of the apparatus to prevent substantial variation in this speed.

Arrangements of this kind have been so designed that a frictional brake is applied to the drive shaft in response to variations in the speed of rotation or according to the position of centrifugal weights. It has been found, however, that the brake blocks or shoes which are normally made of felt, are subject to a certain wear and tear which makes it difficult to maintain the rotational speed sufliciently constant, especially when slow variations are to be avoided.

According to this. invention, anarrangement 20 comprising centrifugal governor weights is so it operates only to produce a regulator action and remains at rest when speed of rotation is constant.

The invention will be better understood from the following description when considered in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

' Referring to the drawin Fig. 1 illustrates an embodimen 30 tion wherein a centrifugal mec in response to variation in driving speed is utilizedto regulate the speed of the drive motor,

Fig. 2 illustrates a modification wherein the regulation is effected through variation in the 35 pressure of the brak, and

' Fig. 3 illustrates a further modification which -is'applicable either to regulate the speed of the e mover or to vary the pressure of the brake.

Referring to Fig. 1, I is an electric motor driv- 40 ing shaft or spindle H to which centrifugal weights I 8 are attached through springs I 2. In thisarrangement the springs H are connected at their left-hand ends to a collar fixed on the spindle ll and'at their right-hand end are attached to a sleeve I 4 shiftable along the spindle I I. With this sleeve it are rigidly connected two diskslS and it which are spaced aparta slightly greater distance than the diameter of a tiny wheel ll: When the speed of rotation of spindle ll varies above or below the rated or nominal value, the small wheel I1 is caused to revolve in ,one direction or the other, and by way of a step-down gear l8 adjusts a resistance I liwhich in kn cluded in the field or own manner is in armature circuit of the motor l0. distance t of the invenoperated 3 Claims. (01. 188-187) between the circumference of the wheel I! and the two disks l5 and I6 may be reduced in practice to as small a value as 0.05 mm. so that the governor device will be caused to respond even in the presence of extremely slight departures 5 from the'normal speed. In the known arrange-- ments, a far greater shift of the sleeve ll along the spindle l I is required to obtain any appreciable change in the pressure of the felt brake shoes.

The axis of the small 10 wheel i'l-or the journaling thereof is preferably made slightly elastic in order that unduly great mechanical load or stress of this axis may not be occasioned. There may be further provided two rolls 20 and 2| which act as stops. v

Another embodim ent-which is suited forthe drive of the talking machine by means of a spring motor is shown in Fig. 2. This embodiment difiers from that in Fig. 1 in that, on the part of the wheel I1 and a step-down gear (not shown) and a worm 22 as well as a worm wheel 23 the pressure of a brake shoe 24 made of felt or the like is altered. According to this embodiment,,the sleeve I 4 has to be changed in position 25 in the direction of spindle ll only the small amount which will sunice to cause actuation of the wheel |1, whereas in the forms of construction known in the past required a shift which caused anappreciable change in frictional action of the brake shoes. The change in the frictional efiect which, of course, in the embodiment Fig. 2 is likewise necessary, is here insured by an adjustment of the brake block 24.

a The third embodiment shown in Fig. 3 differs from that of Fig. 1 in that a disk I 5 is secured upon the sleeve ll between two small wheels i1 and l "I" which are capable of being actuated by the wheel l5 and operate through the inter- 0 mediary of a step-down gear upon wheels 26' and 26" of a differential gear 21. The planetary wheel 28 of this gear and thus the output spindle 29, according to the departure from the rated speed of rotation, will be shifted in one sense or the other, and thereby will work on a resistance 19 as shown in Fig. 1 or a brake-shoe 24, as in Fig. -2.

I claim: l. The combination of a driven shaft, 8. pair -of members rotatable with and slidable along and shaft, a brake including a brake shoearranged to cooperate with one of said members, a roller interposed between said members and connected to said brake for controlling the pressure 'of said brake on said members and means connecting said roller and said brake.

2. The combination of a drivenshaft, a pair of 'centrifugally-controlied members rotatable with and slidabie along said shaft, a brake including a-brake shoe arranged to cooperate with one of said members, a-roller interposed between said members and connected to said brake for controlling the pre'ssure of said brake on said members and means connecting said roller and said brake.

* sure of said brake on said members and means connecting said roller and said brake for moving said brake on its pivot.

ERWIN GERLACH. 

